This paper draws an inclusive image of the concept of borrowing. After that, it tries to relate the linguistic concept of borrowing to borrowed nouns in Arabic with special emphasis on the gender assignment of borrowed nouns. It studies how words are borrowed in Arabic and tries to explain how gender assignment takes place. The data is from modern Iraqi Arabic, which is one form of modern standard Arabic (MSA). The procedure proposed by leading scholars in the area of borrowing and gender assignment is used in the analysis especially G Corbett (1991). The results show that Arabic follows three tactics in borrowing new words and three ways of respective gender assignment using the semantic and formal criteria.